Me find the unit a) 1/18 b) 1/3 c) 3 d) 18

With both problems. a. s.a. p directions on photo ^

Due to bad planning, two of the local schools have their annual plays on the same weekend. while 457 people attend one, and 372 attend the other, only 104 people were able to attend both. how many people went to at least one play?

Perry observes the opposite parallel walls of a room in how many lines do the plains containing the walls intersect